Operation Of Thermal Power Plants Research Articles

Optimization of the Operation of Thermal Power Plants Based on the Use of Motor Mode

Optimization of the Operation of Thermal Power Plants Based on the Use of Motor Mode

Optical microscopy of ceramic materials based on fly ash from thermal power plants

The data on the annual release of ash and slag waste as a result of the operation of thermal power plants (TPP) in Siberia and the Far East of the Russian Federation are presented. The main reasons for the insignificant use of ash in the construction industry (about 5-8% of the total waste output) and the problems hindering its use for the production of ceramic wall materials are considered. A brief description of the composition and properties of the raw materials used in this work for the manufacture of ceramic wall materials is given. The compositions of the developed fly ash-based charges and the method of manufacturing ceramic samples with a matrix structure are given. The results of the study of the structure of ceramic materials by optical microscopy are presented. It is established that during the firing process, a matrix (dispersion medium) is formed from the fusible shell of aggregated complexes, and granules from fly ash are transformed into cores (dispersed phase) of a ceramic matrix composite. It was revealed that the kernels have an oval shape due to the deformation of the granules during pressing. Clusters are formed in the nuclei, consisting of a large number of small crystalline grains connected by an amorphous substance and edged with thin chains of pores. It is shown that the developed pore space inside the cores is mainly represented by frost-proof and reserve pores, which ensures high frost resistance of ceramic samples based on fly ash.

Increasing variable renewables in coal-based energy systems under high electrification in the transport and heating sectors: The case of Kosovo

The increasing penetration of variable renewables poses major challenges in energy systems with limited flexibility. However, there are many solutions to support variable renewable integration when utilizing potential synergies among the different energy sectors. This research examines the technical and environmental effects of electrifying the transport and heating sectors in a coal-based energy system with limited flexibility, aiming to support the integration of variable renewable energy. Scenario analysis is employed to evaluate the use of heat pumps with thermal storage (power-to-heat) for individual heating solutions, electric vehicles, and Vehicle-to-Grid in the transport sector. These measures are evaluated as the primary means for enhancing the energy system flexibility to accommodate a larger share of variable renewables. Additionally, a dynamic analysis was conducted on thermal power plant operational capacities and efficiencies under varying electrification rates and renewable energy shares. The analysis is developed in the EnergyPLAN model using Kosovo energy system as a case study. The results confirm that the electrification of the heating and transport sectors positively impacts the integration of variable renewable energy by reducing critical excess electricity production and CO2 emissions, while power-to-heat and Vehicle-to-Grid facilitate synergies among different energy sectors. However, scenarios with high shares of variable renewable energy present challenges for the nominal operation of thermal power plants, potentially leading to lower operational efficiencies and slightly higher CO2 emissions compared to scenarios where thermal power plant part-load efficiency remains unchanged.

Optimization of the Load Command for a Coal-Fired Power Unit via Particle Swarm Optimization–Long Short-Term Memory Model

This study addresses the challenges faced by coal-fired power plants in adapting to energy fluctuations following the integration of renewable energy sources into the power grid. The flexible operation of thermal power plants has become a focal point in academic research. A numerical model of a coal-fired power plant was developed in this study using the Long Short-Term Memory (LSTM) algorithm and the Particle Swarm Optimization (PSO) algorithm based on actual operation data analysis. The combined PSO-LSTM approach improved the accuracy of the model by optimizing parameters. Validation of the model was performed using a Dymola physical simulation model, demonstrating that the PSO-LSTM coupled numerical model accurately simulates coal-fired power plant operations with a goodness of fit reaching 0.998. Overall system performance for comprehensively evaluating the rate and accuracy of unit operation is proposed. Furthermore, the model’s capability to simulate the load variation process of automatic generation control (AGC) under different load command groups was assessed, aiding in optimizing the best load command group. Optimization experiments show that the performance index of output power is optimal within the experimental range when the set load starts and stops are the same and the power of load command γ = 1.8. Specifically, the 50–75% Turbine Heat Acceptance (THA) load rise process enhanced the overall system performance index by 55.1%, while the 75–50% THA load fall process improved the overall system performance index by 54.2%. These findings highlight the effectiveness of the PSO-LSTM approach in optimizing thermal power plant operations and enhancing system performance under varying load conditions.

Features of the Mechanism of Gas-phase Ignition of Wood Biomass Particles

ABSTRACT Use of woody biomass instead of coal as fuel for thermal power plants (TPP) is considered a promising direction for reducing emissions of anthropogenic substances during the operation of coal-fired thermal power plants. But the process of replacing coal with wood in the thermal power industry is happening very slowly due to objective reasons. The main one is the deposition of particles that have not fully passed the pyrolysis stage (in this case, a layer of substance in a resinous state is retained in the wood particle) on heating surfaces (for example, superheaters) and a decrease in the efficiency of using the heat of combustion of fuel as a result of contamination of the heating surfaces. Therefore, when developing technologies for burning dispersed wood in the furnaces of boiler units, reliable experimental data are required on the characteristic times of ignition and combustion of woody biomass particles, taking into account the time of transition from local (focal) gas-phase ignition to the combustion of volatiles in the entire vicinity of the particle (tsf). The article presents the results of experimental studies of flame propagation processes in the small vicinity of a particle during the ignition period. The experiments made it possible to establish that the flame propagation velocity in the small vicinity of the particle significantly depends on the ambient temperature. It is shown that under conditions of low-temperature heating (air temperature Tg = 873 K), the propagation velocity of the combustion (flame) is minimal. An increase in Tg values (from 873 K to 1273 K) leads to a significant (4–5 times) increase in the time of complete flame coverage of the particle. According to the results of the experiments, two heating modes were identified: high-temperature and low-temperature with a conditional interface Tg = 873 K. At Tg = 873 K, the characteristic particle size of wood biomass has no significant effect on the characteristics and conditions of flame propagation in a small vicinity of the particle. An increase in the ambient temperature (up to 1273 K) leads to an increase in the influence of particle size on the characteristics and conditions of flame propagation. A hypothesis describing the process of flame propagation has been developed.

Thermal energy storage integration for increased flexibility of a power plant with post-combustion CO2 capture

Flexible operation of thermal power plants will become increasingly relevant in the coming years. This work evaluates the effect of integrating a steam accumulator into a 598 MW supercritical coal-fired power plant with moving bed temperature-swing adsorption CO2 capture. Charging the accumulator with reheat steam from the turbine train can reduce the net power output by up to 1.4 % (8.2 MW) for around 200 min. Small charging flow rates are recommended to maximize the final pressure of the accumulator. Covering the sorbent regeneration duty and meeting the demand of two feedwater heaters were considered as alternatives for discharging of the accumulator. Thermal storage discharging was found to give relative power plant load increases between 1.7 and 11.2 % (10.2–66.9 MW) for up to 37.5 min, which exceeds the requirement for primary reserve. Increases in the electrical energy output of 10.5–11 MWh were achieved. The flexibility modes studied in this work are compatible with high CO2 recovery rates.

ISSUES OF WATER USE IN THERMAL POWER PLANTS. PROBLEMS AND SOLUTIONS

The article considers the most effective methods of water treatment for thermal power plants. Water treatment is one of the most important processes in the operation of thermal power plants (TPP). The quality of water treatment for use in boiler units of thermal power plants is of fundamental importance to ensure the efficiency and durability of process equipment. This article reviews the main aspects of water treatment in TPP plants, including treatment methods, water quality characteristics and standards, and the impact of water treatment on the overall energy efficiency and safety of power generation in TPP plants.

An Opportunity for Coal Thermal Power Plants Facing Phase-Out: Case of the Power Plant Vojany (Slovakia)

The study deals with the possibilities of using alternative types of fuels to produce electricity. Power Plant Vojany (PPV) is a thermal power plant (TPP) in eastern Slovakia, which is part of the company Slovenské elektrárne, a. s. (SE). PPV primarily used black coal to produce electricity, which had to be imported from abroad (the Russian Federation). This activity has become inefficient both economically and environmentally, due to the high price of CO2 permits and the high emission factor of this type of fuel. PPV decided to co-combust biomass and refuse-derived fuel (RDF), which resulted in much better economic conditions due to their price, economic efficiency, and partly closed CO2 cycle. The aim of the paper is to explore the possibilities related to the production of energy in the cleanest possible way and with the least possible damage to the environment in coal thermal power plants using the example of operating Power Plant Vojany located in eastern part of Slovakia and to inspire each other for the modern transformation. For the purposes of hypothesis verification, analytical methods focused on overview studies of average fuel prices, comparisons, and the balance of fuels in connection with eliminated CO2 emissions, as well as municipal waste (MW) management in the EU and V4 countries, were used. The authors also focused on the energy recovery and combustion of MW and tracking the achieved CO2 savings in connection with the development of fuel sources in PPV. The results point to the fact that PPV is one of the power plants that could use biomass and RDF as fuel, which confirms the economic advantages of this procedure. The results confirm that the potential of RDF production in Slovakia is sufficient to ensure the operation of PPV at planned, even higher volumes of electricity production. The transformation to cleaner operation of coal thermal power plants represents a significant contribution of this study.

Proposal design and thermodynamic analysis of a coal-fired sCO2 power system integrated with thermal energy storage

It is essential to develop supercritical carbon dioxide (sCO2) power systems integrated with thermal energy storage (TES) to achieve efficient and flexible operation of thermal power plants. This study proposes a novel integrated configuration of the sCO2 coal-fired power system and TES. The extracted sCO2 from the high-pressure turbine inlet is utilized as the source of the stored heat, and the extracted heat is used for storage, work, and recovery in steps to decrease the feasible lowest power load ratio. While in the discharging process, the stored energy is used to heat the branched sCO2 to increase the output power. Thermodynamic models for both design and off-design conditions are developed, and the multi-parameter optimization is carried out by genetic algorithm aiming at the highest energy efficiency. The energy conversion characteristics of the heat storage/release process are obtained, and the impacts of variations in the sCO2 extraction ratio and the initial temperature of the molten salt on the performance are analyzed. The results indicate that the adjustable power load range of the integrated system widens with an increase in the sCO2 extraction ratio. When the extraction ratio reaches its maximum value of 0.2749, the minimum power load of the charging process can reduce from 30 % of the rated load to 10.47 %, and the load of the discharging process can increase from 75 % of the rated load to 88.20 %, thus enhancing the operational flexibility. At this point, the round-trip efficiency of the TES system is 67.56 %, which is mainly limited by the performance of the charging process, especially the throttling loss of the turbine. Furthermore, as the temperature of the molten salt cold tank increases, the heat storage capacity decreases, while the minimum power load of the unit increases, thereby reducing the system's flexibility.

Impact of change in coal quality on operating parameters of Thermal Power Plant Stanari and its risk assessment

The technical and technological characteristics of the Stanari Power Plant block were designed based on the results of the analysis of coal samples from the Raskovac opencast mine. There have not been any notable variations in the coal quality during the Stanari thermal power plant?s present operating term from the project?s stated values. For the expected lifetime of mine, i.e., the thermal power plant operation until 2050, it is necessary to unearth the total remaining available coal reserves from the Stanari basin. The thermal power plant?s operation may be significantly impacted by variations in coal quality at the Ostruznja opencast mine. The use of coal with quality parameters lower than designed can cause problems in the operation of the boiler, stoppages in operation, and an increased volume of maintenance and overhaul of the boiler. Coal quality control in the process of sampling, mining, transportation, and depositing of coal must be at a level that enables smooth operation of the thermal power plant. This paper presents test results during the operation of the thermal power plant burning coal of different quality, (lower calorific value in range from 9100 kJ/kg to ? 7500 kJ/kg), a risk assessment of long-term planning, and the effectiveness and economy of the thermal power plant operation. The potential economic effects and reliability of the operation of thermal power plants due to the increased consumption of coal, limestone and self-consumption in operating modes with significantly lower coal quality than designed were analyzed in particular.

Methods of using waste from steam-gas thermal power plants

At present, the composition of steam and condensate in periodic motion during 45кthe continuous operation of thermal power plants is getting worse and worse. Great importance is attached to the prevention of industrial wastewater pollution. In industry, water is used as a raw material and energy source, as a coolant or heater, as a solvent and extractant, and it is purified in wastewater treatment plants and discharged back into water bodies. Therefore, it is important to further improve the engineering work of wastewater treatment in water conservation. Water is the main technological raw material for obtaining steam in thermal power plants. It is the most widely used product in the continuous operation of the plant.

ANALYSIS OF THE EXPERIENCE OF USING ASH SLAG MATERIALS OF THERMAL POWER PLANTS IN ROAD MATERIALS MADE BY COLD RECYCLING TECHNOLOGY

Summary. This scientific text examines the analysis of domestic and world experience of using ash slag materials of thermal power plants in road materials produced by cold recycling technology. Coal is the most important primary source of energy in Ukraine. In 2019, its share accounted for 28.9% of all energy resources. There are 15 coal-fired power plants in Ukraine, the total capacity of which is 30-40% of the total installed power generation capacity in the country. As a result of the operation of thermal power plants (TPP), a significant amount of large-tonnage waste - ash and slag materials (ZShM) is generated. 360 million tons of ash slag are accumulated in TPP ash dumps. About 5-10 million tons of ash and slag are produced annually. Therefore, there is a question of reducing waste materials as materials for road construction. In Ukraine, the main method of using fly ash materials is their use in the production of cement. But at the current level of cement production, the potential of using slag in this industry has been exhausted. Therefore, the question of using ash slag materials in other industries arises. As an option, it is the use of ZSHM in road construction. Key words: road, road clothing, ash and slag materials, hydroremoval ash, takeaway ash, recycling.

Chemical properties and ecological condition changes of the degraded soils as a result of industrial activities

The article describes the man-made degradation of irrigated soils, resulting from chemical pollution, changes in soil chemistry, and heavy metal pollution during thermal power plant operation. According to the results, the pH value of the soil fell from 7.2 to 6.1 as a result of man-made degradation, ie the acidic environment increased as a result of pollution. Also, some heavy metals, including As - increased by 4.2 times, Cr - by 16 times, Ni - by 2.5 times, Rb - by 3.7 times, Zn - by 4.8 times. Changes in soil environment and soil ecological status have resulted in deterioration in fertility rates and negatively impacted crop yields and quality.

Cooperative Operation of Distributed Energy Resources and Thermal Power Plant With a Carbon-Capture-Utilization-and-Storage System

Carbon-capture-utilization-and-storage (CCUS) system plays a critical role in the process of decarbonization. This paper proposes a cooperative operation model for a CCUS-based thermal power plant and distributed energy resources. The critical purpose is to achieve a higher profit and flexibility together with a lower carbon emission for the CCUS system under the electricity, carbon, ancillary services, and synthesis fuel markets. First, to enhance the operational flexibility in various markets, a critical focus of this paper is on elaborating feasible operation domain of the CCUS system through identifying the physicochemical processes associated with carbon dioxide (CO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) treatment and multi-energy conversion. Second, a Nash-bargaining framework is developed to describe how the CCUS works with distributed energy resources cooperatively to consume cheap and clean renewables to treat CO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> . Third, to solve the cooperative operation problem efficiently and accurately, an adaptive sequential cone programming (ASCP) method together with a progressive hedging variant of the Benders decomposition (PH-BD) algorithm are designed. Case studies indicate the total revenue of the thermal power plant under the cooperative mode is improved by up to 8.85% and 66.53% compared with the individual mode with and without the CCUS. Further, the solution quality and efficiency of proposed methods are verified.

Analysis and evaluation of key influencing factors on the optimization of thermal energy consumption in industrial thermal power plants

In the past, the design and operation of industrial thermal power plants did not give importance to energy consumption. Due to the depletion of fossil fuel reserves and the rising of their prices, restrictions in emission of waste gases into atmosphere, and the need to reduce production costs over the last thirty years, greater attention has been paid to optimizing thermal energy consumption. Various technical, technological, and organizational measures are undertaken to reduce thermal energy consumption. This study examines the proposals for improving the efficiency of thermal energy production in four thermal power plants in Bosnia and Herzegovina. The activities aimed at improving energy efficiency are consolidated and presented through five measures. To determine the optimal measure, the criteria for evaluating each measure are defined. These criteria are analyzed and filtered by using the ISM method, and while the fuzzy AHP method was used for their weights. Finally, the fuzzy TOPSIS method for multi-criteria optimization is applied to select the optimal energy efficiency measure for the analyzed thermal power plants. Additionally, the research defines the order of implementing the selected measures to improve the energy efficiency of the studied thermal power plants.

A computer vision approach to improve maintenance automation for thermal power plants lubrication systems

PurposeLubricating oil leakage is a common issue in thermal power plant operation sites, requiring prompt equipment maintenance. The real-time detection of leakage occurrences could avoid disruptive consequences caused by the lack of timely maintenance. Currently, inspection operations are mostly carried out manually, resulting in time-consuming processes prone to health and safety hazards. To overcome such issues, this paper proposes a machine vision-based inspection system aimed at automating the oil leakage detection for improving the maintenance procedures.Design/methodology/approachThe approach aims at developing a novel modular-structured automatic inspection system. The image acquisition module collects digital images along a predefined inspection path using a dual-light (i.e. ultraviolet and blue light) illumination system, deploying the fluorescence of the lubricating oil while suppressing unwanted background noise. The image processing module is designed to detect the oil leakage within the digital images minimizing detection errors. A case study is reported to validate the industrial suitability of the proposed inspection system.FindingsOn-site experimental results demonstrate the capabilities to complete the automatic inspection procedures of the tested industrial equipment by achieving an oil leakage detection accuracy up to 99.13%.Practical implicationsThe proposed inspection system can be adopted in industrial context to detect lubricant leakage ensuring the equipment and the operators safety.Originality/valueThe proposed inspection system adopts a computer vision approach, which deploys the combination of two separate sources of light, to boost the detection capabilities, enabling the application for a variety of particularly hard-to-inspect industrial contexts.

Application of Model-based Deep Reinforcement Learning Framework to Thermal Power Plant Operation Considering Performance Change

In recent years, there have been increasing expectations for the development of advanced plant operational support systems that can automate complex tasks and autonomouslyoptimize operational procedures in thermal power plants. The performance of the equipment changes during operation and maintenance; hence, it is necessary to adjust the operating process to satisfy the operational constraints. In this study, we investigated a framework based on model-based deep reinforcement learning for acquiring control methods that are robust to changes in equipment performance using a digital twin model. A case study of the operational planning of a thermal power plant was presented and it was demonstrated that a stable control system can be constructed even when plant characteristics are changing.

A Study on The Projection of Coal-Fired Thermal Power Plants

In this study, the main countries with high coal-fired power plant installation capacity and Türkiye, which are among the first in the world in electricity production in this field, and Türkiye are discussed, and parameters such as the installed power and capacity developments of the coal-fired power plants in these countries, electrical energy production values and CO2 emissions from fossil fuels have been evaluated over the years. Emissions from fossil fuels have been evaluated over the years. In this study, predictions about the future of coal-fired power plants were tried to be made by making projection studies. Analysis results are indicated and interpreted with figures and tables. When projections are made according to the current situation, it is predicted that in 2030 and 2050, China will be the first in coal-fired power plant installed power development and electricity production, and accordingly in CO2 emissions from fossil fuels. In addition, the capacity utilization rates, which are an important parameter regarding the efficient operation of coal-fired thermal power plants and their age, have been determined for certain countries over the years. In this study, the country with the highest capacity ratio, with a capacity ratio of around 90%, was determined as Japan. Today, in connection with the re-emergence of coal with the emergence of the energy crisis, energy production planning, and projection studies gain strategic importance for each country. In the literature, country-based projection studies for coal-fired power plants are insufficient and limited. Comprehensive projection study in this area contributes to the studies in the literature.

Modelling of automated steam coal transportation and enrichment systems for efficient operation and cost reduction of thermal power plants

This paper investigates the efficiency of fuel enrichment to reduce the costs of thermal power plants (TPPs). An objective function is formulated to define and measure the desired results. The annual costs of TPPs and additional costs associated with the use of highly abrasive coal are analyzed. The costs of enrichment, in particular, flotation enrichment, are considered. A cost analysis and a transportation problem are presented to demonstrate the results. In general, this paper provides insight into the financial implications of fuel enrichment strategies for thermal power plants.

Effect of Flexible Operation on Residual Life of High-Temperature Components of Power Plants

Electricity generation from renewable energy sources is emerging as a result of global carbon emission reduction policies. However, most renewable energy sources are non-dispatchable and cannot be adjusted to meet the fluctuating electricity demands of society. A flexible operation process has been proposed as an effective solution to compensate for the unstable nature of renewable energy sources. Thermal load fluctuations during flexible operation may cause creep–fatigue damage to the high-temperature components of thermal power plants, as they are designed with a focus on creep damage under a constant power level. This study investigated the residual life of high-temperature components, such as a superheater tube and a reheater header, to failure under flexible operation conditions using finite element analysis and empirical models. First, we determined an analytical solution for the straightened superheater tube under thermal conditions and compared it with the numerical solution to verify the numerical models. Through the verified finite element model, the creep–fatigue life of the reheater header was estimated by considering flexible operation factors and employing the Coffin–Manson and Larson–Miller models. Although fatigue damage increases with decreasing minimum load and ramp rate, we confirmed that creep damage significantly affects the residual life during flexible operation. In addition, a surrogate model was proposed to evaluate the residual life of the reheater as a function of the flexible operation factors using the machine learning methodology, based on the results of finite element methods. It can be used to predict its residual life without performing complex thermo-structural analysis and relying on empirical models for fatigue and creep life. We expect our findings to contribute to the efficient operation of thermal power plants by optimizing the flexible operation factors.